AD&D Climbing Expedited

Everyone knows that thieves in AD&D can climb. Climbing ability increases as the character increases in level. The race of the character can influence how well they climb. Turns out the stumpy legs of a dwarf aren’t so great for climbing.

An obstacle is defined by its height (or width if a horizontal surface must be traversed) and condition of the surface. The condition of the surface determines how far is traversed for each successful roll.

The general procedure is to divide the distance of traverse by the foot per round to determine how many rounds of climbing it will take to overcome the obstacle. For example a Fifty foot tower with a somewhat rough, non-slippery surface would be 50/12 = 4.2 = five rounds of climbing. Which would mean five successful climb rolls are needed to scale the tower.

But what about very tall surfaces? The Conan story The Jewels of Gwahlur (aka The Servants of Bit-Yakin) starts with Conan free climbing a cliff that’s about two hundred feet tall. Given rough and non-slippery conditions that would require nine rolls. The taller the object, the more tedious the rolling will be.

There’s a way to expedite the rolls before you get repetitive stress syndrome. I’ve used statistics to calculate the cumulative chance of failure over many rounds for tables below. The tables cover surface type, race, and level of climber. Note for Assassins, read the tables as two levels lower than the level of the assassin.

To use the tables:

Determine the surface type and associated climbing rate.
Divide the distance to be climbed (vertically or horizontally) by the climbing rate. This value is the number of rounds climbed.
Use the character level (rows) and rounds to be climbed (columns) to determine the percentage change of failure.
Roll the percentage to determine if they fail. Not: rolling equal to or lower than the shown value indicates failure.
If the character fails (and hence falls), then roll randomly to determine which round the fall occurred. Multiply the round number by the climb rate to determine the height fallen.

There are a few things to observe from the calculations.

Dwarfs, Gnomes, and Halflings are unable to climb slippery surfaces.
Half-orcs at 8th level are unable to fail a climb roll.
Humans/Elves/Half-elves must be at least 6th level to climb slippery surfaces.
Half-orcs need only be second level to climb slippery surfaces.

If the object is extremely tall then multiple rolls will still be needed. It will still save some effort. For example, the face of El Capitan is 2900 feet or so. This would be 121 rolls (2900 ft/24 ft). Using the the 14 round column on the tables reduced this to nine rolls (121/14). So a twelve level human master thief would need to make nine rolls of 12 or better to free-climb El Capitan. Pretty good odds (about 35% chance of success). Even a 17th level human would only have about a 69% chance of success. Which leads me to believe Alex Honnald might be a half-orc. Then again the 121 rounds up the cliff is only two hours, whereas Honnald took near four hours to complete it. A DM might adjudicate that being slow and extra careful increases the odds. After Honnald did complete the climb with a partner at 1:58, pretty much dead on the AD&D estimated climb time. And, PCs are supposed to be at the top of their game.

If anyone wants to check the math, feel free to let me know if I made any mistakes.

Non-Slippery Surfaces

Human/Elf/Half-elf